My power seat on my 2000 Cherokee just went caput. I found some 99 GC tracks with driver pair power seat motors on them. The driver track has a memory control box. Both have wiring for seat heaters. I don't know if they would work on a 2000 Cherokee.

I am assuming they wouldn't but I haven't been able to completely rule it out as of yet.

I saw other threads about putting Grand Cherokee seats on Cherokee rails, but nothing about using Grand Cherokee rails.

Grand cherokee rails will not be a direct bolt in.
They can be used only with moderate fabrication. I believe the front mounting points match up but the tabs must be bent, the rears may need something like welded angle iron and drilling to mount in stock location.
Not 100% sure, others will chime in.

Using bits and pieces of info from all the available write-ups, I swapped in ZJ leather/heated/power seats front and rear.
I just unbolted the seats from the rails. However my xj only had power driver seats, the passenger seat is powered, but is bolted to my manual rail. the passenger seat is stuck in a gangster lean until I can swap in the ZJ rail...

By some minor miracle I was able to get power seat rails from a 99 Jeep Cherokee. Even more suprisingly for $80 all of the power seat functions work now. I didn't have time to do it myself so my garage did it for me and they were shocked that I was able to find a replacement so fast and relatively cheap.